The present invention generally relates to friction liners for use in a braking system as, e.g., employed in vehicles, including, but not limited to, cars, trucks, motorcycles, bicycles, snowmobile and the likes.
The prior art describes various approaches relevant to brake systems:
Meckel et. al. in US 2012/0118686 disclose a brake disk made of various steels or a ceramic composite material coated with a material which provides for the coated surface to have a variety of “textured” appearances. The coating provides wear and corrosion resistance and includes a first layer of a metal, such as a pure titanium metal, and a second layer that can include a Nitride, Boride, Carbide or Oxide of the metal used in the first layer. The coating can be applied using a physical vapor deposition source such as a cathodic arc source with a controlled gas atmosphere.
Meckel et. al. in US US2011/0048871 disclose a vehicle braking system which includes a rotating braking element containing a bulk structural material and a friction surface. The friction surface can include an outer coating that includes a corrosion and wear-resistant material. The outer coating can include a decorative color whose color and original appearance are substantially retained after repeated uses in stopping or slowing the vehicle.
Kimihiko et. al. in JP01-153826A2 (1987) disclose light weight and high strength disk brake rotors by joining a rotor body made of an aluminum alloy and a rotor sliding member made of stainless steel together via an intermediate layer made of a nickel-aluminum intermetallic compound to reduce the generation of thermal fatigue on the joined portion due to repeated braking action caused by the different thermal expansion coefficients.
Hampton et. al. in US 2009/0026025 disclose a brake rotor for a vehicle which contains a first coating of a ceramic anti-wear material on a cast iron disk to provide an annular friction surface for braking engagement with a brake pad. The disk has a second coating different from the first coating adhering to the disk to provide an annular non-braking surface spaced from the friction surface. The non-braking surface provided by the second coating is resistant to corrosion.
Hanna et. al. in US 2007/0062768 disclose a friction damped disk brake rotor including a ceramic coating on an insert, wherein the insert has a body with tabs extending therefrom to hold the insert in a desired position within a mold.
Smolen et. al. in U.S. Pat. No. 5,224,572 (1993) disclose a light weight brake rotor including an aluminum rotor having an inner section integrally formed with an outer section and a braking surface containing a ceramic coating comprised of at least one of aluminum oxide, aluminum, titanium and magnesium zirconate. A plurality of circumferentially and radially spaced cooling apertures is provided between the sections to vent heat away from the disk and keeps the temperature of the aluminum rotor below 127° C.
Ohzora et. al. in U.S. Pat. No. 4,808,275 (1989) disclose a rotor for a disk brake coated with nickel containing ceramic particles having a thickness of at least 2 μm, thereby improving corrosion resistance while minimizing torque fluctuation of the rotor during braking. The nickel coating is formed on the surface of the rotor by composite plating in which nickel and the ceramic particles are simultaneously electrodeposited on the surface of the rotor. An annular jig surrounding the outer periphery of the rotor is used to insure a uniform coating thickness.
Hara et. al. in US 2007/0068750 disclose bicycle disk brake pads used in a disk brake device for a bicycle in which a friction member is bonded to a backplate by a diffusion bonding method. The bicycle disk brake pad has a backplate, a spray coating layer and a friction member. The surface of the backplate is covered with a layer of copper or a copper alloy applied by spray coating. The friction member formed by calcination of powders is bonded to the spray coating layer by a diffusion bonding method. Preferably, the spray coating surface is rough.
Kent et. al in U.S. Pat. No. 6,080,493 (2000) describe tank treads, brake linings, rifles stocks, and other devices requiring the bonding of metal to rubber, epoxy, or plastic, with a layer of metal foam interposed between the metal and the rubber or plastic.
Loszewski et, al. in U.S. Pat. No. 7,168,534 (2007) describe an improved clutch or brake device in which at least two members are mounted for relative rotation and engagement. The friction material has a solid density of greater than 30% and includes an open lattice of carbon ligaments forming a network of three dimensionally interconnected cells; and a pyrolytic carbon coating on the open lattice of carbon ligaments.
The prior art describes various coarse-gained, grain-refined and amorphous metallic materials which can be monolithic or layered:
Erb et. al. in U.S. Pat. No. 5,352,266 (1994) and U.S. Pat. No. 5,433,797 (1995), which are assigned to the same assignee as the present application, describe a process for producing nanocrystalline materials, particularly nanocrystalline nickel. The nanocrystalline material is electrodeposited onto the cathode in an aqueous acidic electrolytic cell by application of a pulsed current.
Palumbo et. al. in U.S 2005/0205425 and DE 10228323, both being assigned to the same assignee as the present application, disclose a process for forming coatings, layers or freestanding deposits of nanocrystalline metals, metal alloys or metal matrix composites. The process employs tank plating, drum plating or selective plating processes using aqueous electrolytes and optionally a non-stationary anode or cathode. Nanocrystalline metal matrix composites are disclosed as well.
Tomantschger et. al. in U.S. 2009/0159451, assigned to the same assignee as the present application, disclose graded and/or layered, variable property electrodeposits of fine-grained and amorphous metallic materials, optionally containing solid particulates.
Facchini et. al. in U.S. Pat. No. 8,309,233 (2012), assigned to the same assignee as the present application, disclose fine-gained and amorphous metallic materials comprising cobalt of high strength, ductility and fatigue resistance.
Tomantschger et. al. in U.S. 2010/0304065, assigned to the same assignee as the present application, disclose metal-clad polymer articles comprising polymeric materials having fine-grained (average grain-size of 2 nm to 5,000 nm) or amorphous metallic materials of enhanced pull-off strength between the metallic material and the polymer which are optionally wetproofed.
McCrea et. al. in U.S. Pat. No. 8,247,050 (2012), assigned to the same assignee as the present application, disclose metal-coated polymer articles containing structural substantially porosity-free, fine-grained and/or amorphous metallic coatings/layers optionally containing solid particulates dispersed therein deposited on polymer substrates. The fine-grained and/or amorphous metallic coatings are particularly suited for strong and lightweight articles, precision molds, sporting goods, aerospace and automotive parts and other components exposed to thermal cycling and stress created by erosion and impact damage.
Wang et. al. in U.S. 20120237789, assigned to the same assignee as the present application, disclose a metal-clad polymer article. The metallic material has a microstructure which is at least one of fine-grained with an average grain size between 2 and 5,000 nm and amorphous. The metallic material has an elastic limit between 0.2% and 15%. The stress on the polymeric material, at a selected operating temperature, reaches at least 60% of its ultimate tensile strength at a strain equivalent to the elastic limit of said metallic material.
Schreiber et. al. in U.S. Pat. No. 6,547,944 (2003) disclose an electroplating method for forming a nanolaminate structure with layers of substantially a first metal and substantially a second metal including Cu and Ni, which each layer being less than 1 μm in thickness.
Schuh in et. al. in US 2010/0282613 disclose means to tailor the topography of a nanocrystalline or amorphous metal or alloy, which may be produced by any method including electrodeposition. Metals and alloys with a nanocrystalline or an amorphous structure are reported to exhibit superior physical and/or functional properties, such as high strength, high corrosion-resistance and a low coefficient of friction making them particularly suitable for use as surfaces in tribological coatings requiring a low coefficient of friction replacing traditionally used chromium coatings.
Victor et. al. in US 2011/0287223, assigned to the same assignee as the present application, describe articles having exposed metallic surfaces comprising durable, fine-grained and/or amorphous microstructures which, at least in part, are rendered water repellant by suitably texturing and/or roughening the surface to increase the contact angle for fluids including water, thus reducing the wetting behavior of the surface, reducing corrosion and enabling efficient cleaning and drying.
Pierick et. al. in U.S. Pat. No. 8,113,530 (2012), assigned to the same assignee as the present application, describe the use of nanostructured materials in sports equipment specifically human propelled vehicles such as bicycles, specifically the design, manufacture, and construction of bicycle frames and other bicycle components with nanostructured materials deposited onto polymeric or metallic substrates to improve impact strength and wear performance.
Cesarini et. al. in WO 2005/064190 disclose a mechanical device such as disk brake calipers for transmitting the drive force and/or braking force in vehicles made of a nanocrystalline metal alloy, e.g., Al and Mg based alloys, comprising at least 10% per weight of a material having a grain size less than 100 nm.
Schoenung et. al. in US 2006/0153728 disclose bulk nanostructured alloys, such as aluminum 5083 alloys reinforced with 10 wt. % particulate B4C, synthesized by cryomilling and spark plasma sintering. The nanostructured alloys are degassed and consolidated into dense bulk materials using spark plasma sintering. The nanostructured materials are suitable for use in numerous applications including aerospace components and automotive parts
Thus, the prior art does not specifically teach the use of grain-refined or amorphous metals as friction liners in braking applications.